1. Field of the Invention
This invention relates to a stacker for successively stacking cut papers by inserting a cut paper into the lowest paper of previously stacked papers and also for winding a continuous paper as it is successively stacking the cut papers.
2. Prior Art
There is a prior art stacker which comprises a paper receiver having a bottom plate, side plates and a stopper erected on the bottom plate for limiting the feed depth in the paper feed direction, and a paper feed means for feeding papers into the paper receiver along the upper surface of the bottom plate. With such an arrangement of the prior art stacker, the papers fed out of a printer, etc. are fed by the paper feed means and inserted into the lowest paper of the previously stacked papers on the bottom plate and they are further fed until the top ends thereof contact the stopper and successively stacked on the bottom plate.
According to the prior art stacker, a sheet paper or a continuous paper is cut in a given length and the cut paper alone is stacked. Accordingly, in case that the continuous paper wound in a roll is pulled out and fed into the printer, etc. and it is taken out as it is without being cut after the completion of printing, the stacker which is provided at the rear side of the printer, etc., is rather in the way. Therefore, the stacker needs to be removed from the rear side of the printer, etc. in case of collecting the continuous paper as it is.
Furthermore, since the continuous paper discharged from the printer, etc. cannot be disposed of as it is, an exclusive winding device for winding the continuous paper is additionally provided or the continuous paper discharged from the printer, etc. is manually rolled by an operator if the winding device is not provided.
However, it is troublesome to remove the stacker every time the continuous paper is collected as it is or to provide the exclusive winding device on which the continuous paper is wound. In case that the operator winds manually the continuous paper discharged from the printer., etc., it requires human hands since an exclusive operator for performing the winding operation is needed.
Still furthermore, according to the prior art stacker, a newly cut paper is inserted beneath the lowest paper on the stacked papers so that a paper feed force by a paper feed means needs to be strengthened. In case of the continuous paper wound in a roll, it remains curly even if it is discharged from the printer, etc. and cut thereafter. If the top end of the cut paper directs upward while it remains curly, there is a likelihood that the paper is pushed upward and is forced out from the stopper when the cut paper is fed into the stacker and contacts the stopper at the front end thereof.
In such a case, the stacked papers on the bottom plate is pressed from the top surface thereof by a paper press having a weight attached thereto, thereby restraining the float of the paper. However, in case that the weight is attached to the paper press, if the number of papers to be stacked on the bottom plate is increased, the weight of the paper press and the weight of the stacked papers act on or are applied to the paper newly inserted beneath the lowest paper of the stacked papers so that an excessive press force is applied to the newly inserted paper. As a result, there is a possibility that the new paper cannot be inserted beneath the lowest paper of the stacked papers.
Such an inconvenience often occurs in case of the paper like a paper 27' as illustrated in FIG. 13 which has perforations 27a in the width direction thereof. That is, as illustrated in FIG. 14, the paper 27' is held between and fed by a roll-in roller 65 and a pinch roller 67 and is inserted beneath the lowest paper 27' of the stacked papers and then fed to the position of a stopper 33. There is a flash 27b on the rear side of the paper 27' as illustrated in FIG. 15, which is formed at the time of formation of the perforations 27a. In case that the flash 27b is formed on the back side of the paper 27' which is stacked on the bottom plate, if the new paper 27' is inserted beneath the lowest paper of the stacked papers, the front end 27c of the new paper 27' hits the flash 27b of the lowest paper 27' so that the new paper 27' cannot be inserted further, which makes the stacking impossible.